Enjoy hot water on your boat with a dependable Seaward Marine Water Heater.Heat water dockside with 120V AC power or when underway, using engine heat. This water heater features an ignition-protected design, cladded aluminum tank, dual-wall heat exchanger and stainless steel case. Heat exchanger ports are located at the "Front", on the same side as the electrical box and cold in/hot out ports. To protect against galvanic corrosion and extend tank life, use of a magnesium anode is highly recommended. For installation and maintenance, see theSeaward Water Heater Owner's Manual.NOTE: Other Seaward Water Heater options include a choice of a galvanized steel, stainless steel or epoxy-coated aluminum case. Depending on the model, heat exchanger ports can be located at the "Front" or at the "Rear". See the full selection of Seaward Water Heaters.Key Features (This Model) Stainless steel caseAluminum tankFront-located heat exchanger ports20-gallon capacityKey Features (Seaward Line) Multiple versions to suit your installation Available for 120V and 240VHold down brackets welded to inner tank for strengthIntegrated pressure relief valve for safetyPressure relief valve drain tube includedIgnition-protected designMagnesium anode (available separately) strongly recommended to prevent galvanic corrosion of tank